Buggy code:
@ Reversible public class RepetitionRule extends Rule { private static final long serialVersionUID = 2L ; Rule r ; final Repetition repetition ; protected Condition c ; final Set < String > alternateTags ; private abstract class RepetitionMatcher extends NonterminalMatcher { protected LinkedList < Match > matched ; protected LinkedList < Matcher > matchers ; public RepetitionMatcher ( CharSequence cs , Integer offset , Map < Integer , CachedMatch > [ ] cache , Label label , Matcher master ) { } protected boolean grab ( ) { } } private abstract class GreedyAndPossessive extends RepetitionRule . RepetitionMatcher { private final boolean backtracks ; protected GreedyAndPossessive ( CharSequence cs , Integer offset , Map < Integer , CachedMatch > [ ] cache , Label label , boolean backtracks , Matcher master ) { } protected void initialize ( ) { } } private class GreedyMatcher extends RepetitionRule . GreedyAndPossessive { protected GreedyMatcher ( CharSequence cs , Integer offset , Map < Integer , CachedMatch > [ ] cache , Label label , Matcher master ) { } @ Override protected void fetchNext ( ) { } } private class StingyMatcher extends RepetitionRule . RepetitionMatcher { private int goal ; protected StingyMatcher ( CharSequence cs , Integer offset , Map < Integer , CachedMatch > [ ] cache , Label label , Matcher master ) { } private void seekGoal ( ) { } @ Override protected void fetchNext ( ) { } } private class PossessiveMatcher extends RepetitionRule . GreedyAndPossessive { protected PossessiveMatcher ( CharSequence cs , Integer offset , Map < Integer , CachedMatch > [ ] cache , Label label , Matcher master ) { } @ Override protected void fetchNext ( ) { } } public RepetitionRule ( Label label , Rule r , Repetition rep , Set < String > alternateTags ) { } @ Override public Matcher matcher ( CharSequence cs , Integer offset , Map < Integer , CachedMatch > [ ] cache , Matcher master ) { } @ Override protected String uniqueId ( ) { } @ Override public String description ( boolean inBrackets ) { } @ Override public Set < Integer > study ( CharSequence s , Map < Integer , CachedMatch > [ ] cache , Set < Rule > studiedRules , GlobalState options ) { } @ Override public boolean zeroWidth ( ) { } @ Override public Rule shallowClone ( ) { } @ Override public Rule conditionalize ( Condition c , String id ) { if ( ( this . c ) == null ) { this . c = c ; this . condition = id ; } else { if ( ( this . c ) instanceof LogicalCondition ) { if ( ! ( ( ( LogicalCondition ) ( this . c ) ) . replace ( id , c ) ) ) <START_BUG> throw new GrammarException ( ( ( "could<seq2seq4repair_space>not<seq2seq4repair_space>defined<seq2seq4repair_space>" + id ) + "<seq2seq4repair_space>in<seq2seq4repair_space>this<seq2seq4repair_space>condition" ) ) ; <END_BUG> } else if ( ( this . c ) instanceof LeafCondition ) { LeafCondition lc = ( ( LeafCondition ) ( this . c ) ) ; if ( lc . cnd . equals ( id ) ) this . c = c ; else throw new GrammarException ( ( ( ( "rule<seq2seq4repair_space>" + ( this ) ) + "<seq2seq4repair_space>does<seq2seq4repair_space>not<seq2seq4repair_space>carry<seq2seq4repair_space>condition<seq2seq4repair_space>" ) + id ) ) ; } else throw new GrammarException ( ( ( "condition<seq2seq4repair_space>on<seq2seq4repair_space>rule<seq2seq4repair_space>" + ( this ) ) + "<seq2seq4repair_space>cannot<seq2seq4repair_space>be<seq2seq4repair_space>redefined" ) ) ; } return this ; } @ Override protected void addLabels ( Match match , Set < String > labels ) { } @ Override protected void setUid ( ) { } @ Override protected void setCacheIndex ( Map < String , Integer > uids ) { } @ Override protected int maxCacheIndex ( int currentMax , Set < Rule > visited ) { } @ Override protected void rules ( Map < String , Rule > map ) { } @ Override protected void fixAlternation ( ) { } }

Fix:
throw new GrammarException ( ( ( "could<seq2seq4repair_space>not<seq2seq4repair_space>define<seq2seq4repair_space>" + id ) + "<seq2seq4repair_space>in<seq2seq4repair_space>this<seq2seq4repair_space>condition" ) ) ;